Door sealing apparatus



Feb. 8, 1955 c. R. ANDERSON DOOR SEALING APPARATUS Filed May 29, 1955 17 I N VEN TOR.

CHESTER E. Amasesaw United States Patent DOOR SEALING APPARATUS Chester R. Anderson, Los Angeles, Calif.

Application May 29,1953, Serial No. 358,442.

3 Claims. (CI. 20-23) This invention relates to an apparatusfor guiding and hermetically sealing a closure member against an opening in a housing or chamber. More particularly it is directed to a system including in combination means for closing and sealing openings of relatively large areas against air pressures approaching atmospheric pressure.

The difficulties in providing hermeticallysealedclosures generally increase as the size of the opening tobe closed increases. In the case: of relatively large chamber such as the retort chambers employed in vacuum precooling processes for preserving perishable products, for example, the openings to these retorts must necessarily be of a reasonably large area to facilitate movementof the products into and out of the retort. Since these retorts are usually evacuated to an extremely low pressure, the closure member or door itself must be of sufiicient strength to withstand theatmospheric pressure acting on it. This results in relatively massive type doors. In order to insure effectivehermeticalsealing of this door against-the-retort opening, it is important that substantiallyequalforces be applied and maintained against the door. It is also desirable however that such a door be easily moved from open to closed position and vice versa.

It is accordingly a primary object of the present invention to provide a combination door guiding and sealing mechanism that is rugged and thoroughly reliable and wherein certain portions of the specific sealing means are also employed for guiding the door in moving from its open to closed position.

Another object is to provide for a mechanical advantage in the sealing mechanism whereby a larger force may be exerted against the door than is necessary to operate the mechanism.

A further object is to provide means for exerting uniform forces at spaced portions of the door simultaneously to insure a uniform sealing over the entire periphery of the opening.

In accordance with the invention there is provided a closure member having guiding flanges along opposite side edges defining channels adapted to receive roller elements. Each roller element is rotatably mounted on a bell crank type of lever in turn pivoted to a stationary frame such as the retort or chamber which is to be sealed. Another portion of the bell crank lever is pivotally coupled to an actuating rod which serves to swing the bell crank lever about its stationary pivot point to move the roller with a mechanical advantage as to force over a small arcuate distance. Since the roller is confined within the channel defining an edge of the door, the whole door will be moved in a direction normal to the plane of the opening. A suitable seating gasket is provided about the periphery of the opening against which the door is urged by the roller.

In a preferred embodiment of the invention, four such bell crank members and associated rollerelements are provided, one adjacent each of the four corners of the opening. Suitable actuating rods couple the bell crank levers together so that a single actuating force will operate to pivot the bell cranks all simultaneously and insure that a substantially equal force is applied to all four corner portions of the door simultaneously. Preferably a hydraulic cylinder and piston rod arrangement is employed for actuating these rods. The same roller elements and edge channels provide a track permitting the door to 'be moved laterally in its own plane with negligible friction to expose the opening.

2,701,394 .Patented F eb. 8, 1955 ICC A better understanding of. the invention will be had by referring to the accompanying drawings in which Fig. 1 is aperspective view of a retort chamber including atone end'a door. and sealing apparatus designed in accordance with a preferred form of the invention;

Fig. 2 i'san' enlarged elevational view partly in section of the door sealing mechanism;

Fig. 3 is a still larger view of one of the bell crank levers and roller elements employed at one corner portion 0 of the door; and

- end of the cylinder to the other.

Fig. 4 is a cross-sectional plan view as seen along the lines, 4-4 of Fig. 3.

Referring to Fig. 1. there is shown a retort chamber 10 adapted to; be" closed and hermetically sealed atone end by a door member 11. In the preferred form of the invention the door member 11- is moved laterally in its own plane in a vertical direction to expose the opening tothe retort by means of a hoist cable 12 and ahoisting-mechanism designated generally by the numeral 13.

To move the door-1'1 into'sealing positiononce it has closed the opening; there is provided a powermeans comprising a hydraulic cylinder 14 including a piston and piston rod coupled to, suitable actuating rod'members; Hydraulic fluid is fed to the cylinder 14 through small conduits 15 and 16 to-move the piston therein from one The various actuating rods are coupled toupper bell crank type levers 17 and lower bellcrank type levers 18 disposed at the upper and lower cornersof the retort chamber 10.

As shown more clearly in Fig. 2, the door 11 includes along each longitudinal edge a channel member 20 pref erably in the form of an I-beam. which may constitute an integral part? of the door construction. The. channel member: 20 includes-at least one flange 20 defining one of the channel walls and adapted to guide a roller element 21, as shown clearly in Fig. 4.

The roller 21 is rotatably mounted on the bell crank type lever 17 at a position intermediate the ends of the bell crank lever. The lower righthand end of the bell crank is pivotally mounted to a stationary frame, such as the frame of the retort chamber 11 by means of a mounting support 22. The upper end of the bell crank 17 is in turn pivotally coupled to an actuating rod 23, the other end of the rod 23 being connected to a lever 24. The two levers 24 at opposite edges of the chamber are mounted on a rock shaft 24a, so as to swing in unison. Also pivotally secured to one of the levers 24 is one end of a piston rod 25 connecting to a piston within the cylinder 14. The cylinder 14 is pivotally mounted on the support 26 in order that the slight arcuate motion of the piston rod end can be accommodated by small arcuate movements of the cylinder 14. The actuating rod 23 may include a turnbuckle as shown for adjusting its length.

A third end portion of the bell crank lever 17 is pivotally secured to a tie rod 28 as at the pivot point 29, the lower end of the tie rod 28 pivotally connecting to the lower bell crank lever 18 as at 30. The lower bell crank lever 18 similarly mounts a roller element 31 as at the pivot point 32 and is similarly pivoted to a stationary supporting member 33.

As clearly shown in Figs. 3 and 4, the periphery of the opening in retort chamber 10 is provided with a gasket 34 against which the door is urged.

The operation of the door sealing apparatus will be readily understood from the foregoing. In the unsealed position of the door as depicted in Fig. 2 the hoisting mechanism 13 may easily and with negligible friction raise or lower the door 11 to expose or close the opening in the retort 10. It is to be noted that the various roller elements 21 and 31 serve to guide the passage of the door between its open and closed positions. When it is desired to seal the door after it has been lowered into closing position, suitable hydraulic fluid is introduced into the inlet conduit 15 of cylinder 14 to move the piston rod 25 to the right, as shown in Fig. 2, thereby moving the actuating rod 23 longitudinally to swing the bell crank levers 17 about their stationary pivot points 22. This motion also moves the lower bell crank levers 18 by virtue of the tie rod 28 connected therebetween.

As shown in phantom lines in Fig. 3, movement of the bell crank lever about its stationary pivot point causes the roller elements 21 to move to the right against the side flange 20' with a considerably greater force than that applied to the upper pivot point of the bell crank 27 by the actuating rod 23. This greater force results from the fact that the pivotal mounting for the roller element 21 is considerably closer to the stationary pivot support mounting 22 than to the upper pivot coupling at 27 resultingin a mechanical advantage inversely proportional to the ratio of these distances. The action of the roller 21' against the side flange 20 defining the side of the channel 20, is to move the door in a direction normal to the plane of the opening in the retort 11), against the peripheral gasket strip 34. The engaging force as pointed out above, is considerably greater than the power supplied to the actuating rod 23 and is quite sufficient to maintain a hermetically tight seal.

When it is desired to remove the contents of the chamber 10, the actuating hydraulic cylinder 14 is fed with hydraulic fluid through the inlet conduit 16, the fluid on the other side of the piston passing out through the conduit 15. This action moves the piston rod 25 to the left as seen in Figs. 2 and 3, to swing the bell crank levers 17 and the corresponding lower bell crank levers 18 counter-clockwise about their stationary pivot points and thus cam the door 11 away from the opening a suflicient distance to enable the door to be raised by the hoisting mechanism 13.

It is thus seen that the present door sealing mechanism afiords the dual functions of providing rollers for guiding lateral movements of the door to expose the opening in the retort 10 and also to move the door in a direction normal to the plane of the opening to effect an air-tight seal.

Furthermore, the apparatus permits a relatively large force to be exerted for the sealing function by virtue of the bell crank arrangement and the strategic location of the pivoting points and mountings for the guiding roller elements. It will also be noted that the various tie-rod connections 28 permit all four corners of the door to be urged simultaneously against the sealing gasket 34 with substantially the same amount of force.

I claim:

1. In an apparatus for. hermetically sealing a door against a sealing gasket about the periphery of an opening into a chamber, means for urging with substantially equal force the opposite longitudinal edges of said door into engagement with said gasket comprising: channel members on opposite edges of the door, each having a pair of longitudinal roller guiding flanges; rollers adapted to roll in the channels in engagement with said roller guiding flanges; a bell crank lever rotatably mounting each roller and pivotally secured to the chamber; a longitudinally actuating rod member pivotally connected to another portion of each bell crank lever; and power means for moving said rod members to swing said bell crank levers about their pivot points which are secured to the chamber, whereby each roller is caused to bear against a guiding flange of its channel member to move the door in a direction normal to the plane of the opening against the sealing gasket.

2. An apparatus according to claim 1, in which there are provided at least four bell crank levers, one disposed adjacent each of the four corners of said chamber opening, means interlinking said bell crank levers to operate in unison, said door being adapted to be moved laterally in its own plane to expose said opening, the rollers serving to guide said lateral movement of the door.

3. An apparatus according to claim 1, in which said power means comprises a hydraulic cylinder and piston rod arrangement, and means coupling said piston rod to said actuating rod members.

References Cited in the file of this patent UNITED STATES PATENTS 2,199,182 Leonard Apr. 30, 1940 2,612,659 OConnor Oct. 7, 1952 

